1. Field of the Invention
This invention relates to apparatus for effecting the cementing of a liner at the bottom of a well bore by the suspension of the liner from a liner hanger which is engaged with the bottom portions of the well casing through the hydraulic actuation of a running tool which is connected to the work string by a torque transmitting expansion joint.
2. Description of the Prior Art
The cementing of a tubular liner assembly in that portion of the well bore extending downwardly beyond the well casing is an expedient that has been long practiced in the drilling art. It is the common practice to suspend the liner assembly from a hanger which has slips that are expanded to engage the interior bore of the lower end of the well casing. The setting of the hanger anchor is normally accomplished by a running tool which also effects the running-in of the liner assembly and the hanger.
In the past, many hangers have been mechanically actuated to achieve their setting. This necessarily requires mechanical manipulation of the running-in tool by the tubular work string from which it is suspended. For example, see the cementing apparatus disclosed in U.S. Pat. No. 4,060,131 to Kenneday et al.
With modern wells extending to ever increasing depths and often involving directional drilling, the reliability of mechanical setting of the hanger has been adversely affected. Modern drillers may sometimes prefer to employ hydraulically actuated running tools to effect the setting of hangers for cementing operations. At the same time, however, any such hanger and running tool should be capable of mechanical setting in the event that the hydraulic setting system should fail for any unforeseen reason. Prior art hydraulically actuated running tools have not had the capability of transmitting torque through the tool in order to effect such mechanical setting operation. There is, therefore, a definite need for an improved well cementing apparatus, capable of either hydraulic or mechanical setting of the hanger through the utilization of economical, readily available components.